JPH09261677A - Rear projection liquid crystal projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rear projection liquid crystal projector whose contrast is improved. SOLUTION: In the three-panel rear projection liquid crystal projector, a polarization direction of a color light shared by a liquid crystal display panel 143 arranged at a right angle to the other two liquid crystal display panels 141, 145 is in matching with a polarization direction of a color light shared by the liquid crystal display panels 141, 145 by using a phase difference plate 15. Furthermore, the polarization direction of the light after color synthesis is converted by a phase difference plate 17 to be in matching with a polarization direction of a polarization film 13 provided to a screen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection device for magnifying and projecting a reproduced image of a television or the like, and more particularly, to rear projection for projecting an image from the back side of a screen by using a liquid crystal panel as an optical shutter for image reproduction. Type liquid crystal projector device.

[0002]

2. Description of the Related Art Following high-definition broadcasting, terrestrial television broadcasting has also started to be broadcast on a wide screen. Also, with the spread of cable television, the upcoming digital television broadcasting, and the introduction of high-resolution software such as digital video discs, a high-quality large-screen image reproducing apparatus is desired. However, the CRT used in the conventional direct-view display device has a limit of about 40 inches due to the manufacturing technology, manufacturing cost, size and weight of the product, and the like, and a front projection type or rear projection type is required to realize a larger screen. There is a type projector system. Further, these projector systems have a CRT system and a liquid crystal system, respectively, depending on the device that forms the original screen to be enlarged and projected, and although the liquid crystal projector is inferior in the maximum brightness as compared with the CRT projector, the focus performance and the device It is considered to be excellent in terms of size and weight reduction.

FIG. 28 is a system configuration diagram showing an outline of a conventional three-panel rear projection type liquid crystal projector device. In the figure, a conventional rear projection type liquid crystal projector device 1 is shown.
01 is a light source lamp 111 serving as a light source and a light source lamp 1
11, and a parabolic mirror 115 arranged so that the light source lamp 111 is located at the focal point.
A UV / IR filter 117 for cutting ultraviolet rays and infrared rays, dichroic mirrors 121, 123, 133, 135 and total reflection mirrors 125, 131 constituting color separation / combination means, and optical paths for each color-separated color. Liquid crystal panels 141, 143, and 145, and a polarizing plate 15 serving as a polarizer provided on the light incident side of each liquid crystal panel.
1, 153, 155 and polarizing plates 161, 163, 165 serving as analyzers provided on the light emission side of each liquid crystal panel.
, A projection lens 171 for enlarging and projecting the color-combined lights, a Fresnel lens 175 and a lenticular lens 177 serving as a screen, a video input terminal 181 to which a video signal is input, and a liquid crystal panel 14 from the video signal.
1, 143, and 145, and a signal processing circuit 183 that generates a drive signal.

The operation of this conventional rear projection type liquid crystal projector device 101 is as follows. First, a light source lamp 1 using a halogen lamp, a metal halide lamp, etc.
11 receives light from the power supply circuit 113 and emits light. The light emitted from the light source lamp 111 is parabolic mirror 1
The light is controlled and reflected by the light beam 15 into substantially parallel light that is emitted to the right. From the substantially parallel light obtained from the parabolic mirror 115, wavelengths in the ultraviolet and infrared regions which are unnecessary and harmful to image formation are U
It is cut by the V / IR filter 117.

Next, 45 ° with respect to the optical path of the substantially parallel light.
By means of the dichroic mirrors 121 and 123 which form a part of the color separation / combination means arranged at an angle of, for example, blue light (hereinafter abbreviated as B), red light (hereinafter abbreviated as R) and green light (hereinafter abbreviated as G). ), The optical paths of the three primary colors of light are separated.

That is, first, the dichroic mirror 1
B is reflected and separated by 21 and then R is reflected and separated by the dichroic mirror 123.
The remaining G enters the liquid crystal panel 145 via the polarizing plate 155.

B is reflected by the total reflection mirror 131 and enters the liquid crystal panel 141 through the polarizing plate 151. R is incident on the liquid crystal panel 143 via the polarizing plate 153. The B, R, and G lights to which the liquid crystal panels 141, 143, and 145 are provided with the optical rotatory power corresponding to the video signals, are polarizing plates 161, 163, which are analyzers provided on the emission side of the respective liquid crystal panels. After the optical rotatory spatial distribution is converted to a light intensity spatial distribution by 165, the reflecting mirror 1
25 and the dichroic mirrors 133 and 135 perform color combination and enter the projection lens 171.

The Fresnel lens 175 is the projection lens 17
The light emitted from the light source 1 is focused on the observation position, and the lenticular lens 177 controls and / or diffuses the light passing through the Fresnel lens 175 in an arbitrary direction.

On the other hand, a drive signal for controlling the optical rotatory power of each cell of the liquid crystal panels 141, 143 and 145 is generated by the signal processing circuit 183 based on the video signal input to the video input terminal 181, and these liquid crystals are generated. Supplied to the panel.

The rear projection type liquid crystal projector apparatus 101 is housed in a housing in which the front surface of the lenticular lens 177 is exposed, and an image is observed from the right side of the lenticular lens 177 by an observer showing a viewpoint at 191. It

In such a conventional rear projection type liquid crystal projector device, there is a device for improving the contrast by utilizing the fact that the light passing through the optical shutter composed of the liquid crystal panel and the polarizing plate is linearly polarized light. There wasn't.

Further, it is known that at least one reflecting mirror is provided between the projection lens and the Fresnel lens and the optical path from the projection lens to the screen is bent by the reflecting mirror to downsize the rear projection type liquid crystal projector device. However, there is no such device that uses S-polarized light that has a high reflectance and obtains a bright image by utilizing the difference in reflectance depending on the polarization direction on the reflecting surface of the reflecting mirror.

[0013]

However, compared with the front projection type liquid crystal projector device, the conventional rear projection type liquid crystal projector device can see an image without darkening the room. However, there is a problem that the black level of the image rises because of the reflection on the screen, and the contrast of the image decreases according to the ambient brightness.

Further, in the above-mentioned conventional rear projection type liquid crystal projector device, compared with the central portion of the screen, the light intensity and the contrast in the peripheral portion of the screen, particularly in the four corners of the screen are remarkably lowered, and the image in the peripheral portion of the screen is difficult to see. There was a problem.

The present invention has been made in view of the above problems, and a main problem thereof is a rear projection type liquid crystal which is improved so that a decrease in contrast with respect to external light is less than that of a conventional device. A projector device is provided. Another object of the present invention is to provide a screen peripheral portion, especially a screen 4
It is an object of the present invention to provide a rear projection type liquid crystal projector device having improved corner contrast.

Another object of the present invention is a rear projection type liquid crystal projector device in which the optical path from the projection lens to the screen is bent by a reflecting mirror to make it compact, and the polarization direction of light incident on the reflecting mirror is adjusted to be high. It is an object of the present invention to provide a rear projection type liquid crystal projector device that can utilize reflectance.

[0017]

In order to solve the above problems, the present invention has the following arrangement. That is, the invention according to claim 1 is a light source lamp, a parabolic mirror that controls and reflects light emitted from the light source lamp into substantially parallel light, a substantially parallel light obtained from the parabolic mirror, and a dichroic mirror. A color separation / combination means that separates into different paths for each of the three primary colors of light using a total reflection mirror and then re-combines them, and is provided for each of the paths of the light separated into these three primary colors.
An optical shutter composed of a pair of a liquid crystal panel and an analyzer with an oblique rubbing structure, a projection lens for magnifying and projecting the light color-synthesized by the color separation / combination means, and a light emitted from the projection lens is collected at an arbitrary position. A Fresnel lens for emitting light, a lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in an arbitrary direction, a polarizing film arranged at an arbitrary position from the projection lens to the front surface of the lenticular lens, and at least one of A polarization direction conversion unit that is disposed between the optical shutter and the projection lens, and that converts the polarization direction of light that has passed through the optical shutter so as to match the polarization direction of the polarizing film. It is a rear projection type liquid crystal projector device as a gist.

According to a second aspect of the present invention, a light source lamp, an ellipsoidal mirror for reflecting and condensing light emitted from the light source lamp, and light emitted from the ellipsoidal mirror are substantially parallel to the optical axis. And a color separation / combination means for separating the substantially parallel light obtained from the condensing lens into different paths for each of the three primary colors of light using a dichroic mirror and a total reflection mirror, and then recombining the separated light. An optical shutter provided for each of the paths of the light separated into the three primary colors, each of which includes a polarizer, a liquid crystal panel having a diagonal rubbing structure, and a pair of polarizers, and the light color-synthesized by the color separation / combination means is enlarged. A projection lens for projecting, a Fresnel lens for condensing the light emitted from this projection lens at an arbitrary position, and a lenticular for controlling and / or diffusing the light passing through this Fresnel lens in an arbitrary direction. Lens, a polarizing film disposed at any position from the projection lens to the front surface of the lenticular lens, and at least one of the optical shutter and the projection lens, the light passing through the optical shutter. A rear projection type liquid crystal projector device characterized by comprising: a polarization direction conversion means for converting the polarization direction so as to match the polarization direction of the polarizing film.

According to a third aspect of the present invention, a light source lamp, a parabolic mirror that controls and reflects light emitted from the light source lamp into substantially parallel light, and polarization of substantially parallel light obtained from the parabolic mirror. A first polarizing plate that passes a limited direction, and a color that separates the light that has passed through this first polarizing plate into different paths for each of the three primary colors of light using a dichroic mirror and a total reflection mirror, and then recombines them. Decomposition / combination means, a liquid crystal panel having an oblique rubbing configuration provided for each path of light separated into the three primary colors, and only light in an arbitrary polarization direction from the light color-combined by the color separation / combination means. A second polarizing plate that passes the second polarizing plate, a projection lens that magnifies and projects the light that has passed through the second polarizing plate, a Fresnel lens that condenses the light emitted from the projection lens at an arbitrary position, and the Fresnel lens Passed through A lenticular lens for controlling and / or diffusing in an arbitrary direction, and a polarizing film having the same polarization direction transmission characteristics as the second polarizing plate and arranged at an arbitrary position from the projection lens to the front surface of the lenticular lens, At least one polarization direction conversion means arranged to convert the polarization direction, the polarization direction conversion means being disposed between the at least one liquid crystal panel and the projection lens, and passing through the three liquid crystal panels. The rear projection type liquid crystal projector device is characterized in that the polarization direction of the light reaching the polarizing plate matches the polarization direction of the second polarizing plate.

According to a fourth aspect of the invention, a light source lamp, an ellipsoidal mirror for reflecting and condensing light emitted from the light source lamp, and light emitted from the ellipsoidal mirror are substantially parallel to the optical axis. A condensing lens, and a first polarizing plate for limiting and passing the polarization direction of the substantially parallel light obtained from the condensing lens,
The light that has passed through the first polarizing plate is separated into different paths for each of the three primary colors of light by using a dichroic mirror and a total reflection mirror, and is then re-synthesized, and the three primary colors are separated. A liquid crystal panel having an oblique rubbing structure provided for each path of light, a second polarizing plate for selectively passing only light in an arbitrary polarization direction out of the lights color-synthesized by the color separation / combination means, and A projection lens for enlarging and projecting the light passing through the second polarizing plate, and a Fresnel lens for condensing the light emitted from the projection lens at an arbitrary position,
A lenticular lens for controlling and / or diffusing light passing through this Fresnel lens in an arbitrary direction, and having the same polarization direction transmission characteristics as the second polarizing plate, at any position from the projection lens to the front surface of the lenticular lens. The three liquid crystal panels, each comprising: a polarizing film arranged; and at least one polarization direction conversion unit arranged between the liquid crystal panel and the projection lens for converting a polarization direction. The rear projection type liquid crystal projector device is characterized in that the polarization direction of light passing through and reaching the second polarizing plate is the same as the polarization direction of the second polarizing plate.

According to a fifth aspect of the present invention, a light source lamp, a parabolic mirror that controls and reflects light emitted from the light source lamp into substantially parallel light, and polarization of substantially parallel light obtained from the parabolic mirror. A polarizing plate that allows the light to pass in a limited direction, a color separation / combining unit that separates the light that has passed through the polarizing plate into different paths for each of the three primary colors of light using a dichroic mirror and a total reflection mirror, and then recombines the separated light. A liquid crystal panel having an oblique rubbing configuration provided for each of the paths of light separated into three primary colors, a projection lens for enlarging and projecting the light color-combined by the color separation / combination means, and light emitted from the projection lens. , A lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in an arbitrary direction, and the lenticular lens from the projection lens It is located at any position to the surface,
A polarizing film that selectively transmits only light in an arbitrary polarization direction,
Light which comprises at least one polarization direction conversion means arranged between the liquid crystal panel and the projection lens for converting the polarization direction, and which passes through the liquid crystal panel and reaches the polarizing film. The rear projection type liquid crystal projector device is characterized in that the polarization direction of is the same as the polarization direction of the polarizing film.

According to a sixth aspect of the present invention, a light source lamp, an ellipsoidal mirror for reflecting and condensing light emitted from the light source lamp, and light emitted from the elliptical mirror is substantially parallel to the optical axis. A condensing lens, a polarizing plate for limiting and passing the polarization direction of the substantially parallel light obtained by the condensing lens, and the light passing through the polarizing plate by using a dichroic mirror and a total reflection mirror. Color separation / combination means for separating and recombining into different paths for each color, a liquid crystal panel having an oblique rubbing configuration provided for each path of the light separated into the three primary colors, and color combination by the color separation / combination means. A projection lens for enlarging and projecting the emitted light, and a Fresnel lens for condensing the light emitted from the projection lens at an arbitrary position,
A lenticular lens that controls and / or diffuses light that has passed through this Fresnel lens, and a polarized light that is arranged at an arbitrary position from the projection lens to the front surface of the lenticular lens and selectively transmits only light in an arbitrary polarization direction. A polarization direction converting means for converting at least one polarization direction disposed between at least one of the liquid crystal panel and the projection lens, and passing through the liquid crystal panel to form the polarization film. The rear projection type liquid crystal projector device is characterized in that the polarization direction of light that reaches it matches the polarization direction of the polarizing film.

According to a seventh aspect of the present invention, in the rear projection type liquid crystal projector device according to any one of the first to sixth aspects, the polarizing film is arranged outside the lenticular lens. The gist is that a light transmitting plate having an arbitrary transmittance is further provided on the outer side of.

The invention according to claim 8 is the rear projection type liquid crystal projector device according to any one of claims 1 to 6, wherein the polarizing film is arranged outside the lenticular lens, and the lenticular lens is provided. The gist is that a light transmitting plate having an arbitrary transmittance is further provided between and the polarizing film.

According to a ninth aspect of the present invention, in the rear projection type liquid crystal projector device according to any one of the first to eighth aspects, a reflecting mirror is further provided between the projection lens and the Fresnel lens. The polarization direction of the light emitted from the projection lens is S-polarized with respect to the reflecting mirror.

In the rear projection type liquid crystal projector device according to the present invention having the above-mentioned structure, the polarized light which selectively passes only the light having the same polarization direction as the analyzer at an arbitrary position from the projection lens to the front surface of the lenticular lens. By further including the film, when the light passing through the analyzer is observed as an image through the lenticular lens, only the light having the same polarization direction as that of the analyzer is selectively passed by the polarizing film. The light that carries the image is not attenuated and the component perpendicular to the polarization direction of the polarization film of the light incident from the outside of the rear projection type liquid crystal projector device is prevented from being reflected and passed by the polarization film. The dark areas become darker and you can see the image with improved contrast.

Further, in the present invention, by providing the polarization direction conversion means for converting the polarization direction between the liquid crystal panel and the polarizing film, one liquid crystal panel having an oblique rubbing structure and two other liquid crystal panels are provided. Since it is provided at a right angle to the panel, even if the difference in the number of reflections for color combination after passing through the liquid crystal panel and entering the projection lens becomes an odd number, the polarization direction conversion means causes the polarization direction of the liquid crystal panel. Can be converted to align with the polarization directions of the other two liquid crystal panels,
The polarization direction of the light projected on the polarizing film can be aligned.

Further, in the present invention, by providing the polarization direction conversion means in the optical path after the color combination, the polarization film having an arbitrary polarization direction and the polarization direction of the projected light can be matched. The polarization direction of the polarizing film can be matched with the polarization direction having the highest external light reflection preventing effect independently of the rubbing direction of the liquid crystal panel.

Further, in the present invention, the polarizing film provided on the screen also functions as an analyzer, so that the optical shutter function for image reproduction is maintained while the polarizing plate acting as the analyzer is omitted. An improvement in contrast reduction due to outside light is obtained.

In the present invention, the polarizing film is arranged outside the lenticular lens, and the light transmitting plate having an arbitrary transmittance is arranged further outside the polarizing film.
Furthermore, it is possible to improve the contrast and prevent the polarizing film from being damaged by an external force.

Further, in the present invention, in a rear projection type liquid crystal projector device of a type in which a reflecting mirror is provided between the projection lens and the Fresnel lens, the polarization direction of the light emitted from the projection lens is set to the reflecting mirror. By using S-polarized light, the maximum reflectance of the reflecting mirror can be utilized.

[0032]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a system configuration diagram showing a first embodiment of a rear projection type liquid crystal projector device according to the present invention.

In FIG. 1, the rear projection type liquid crystal projector device 1 is arranged such that a light source lamp 111 serving as a light source, a power supply circuit 113 for supplying power to the light source lamp 111, and the light source lamp 111 are located at a focal point. Parabolic mirror 1
15, a UV / IR filter 117 that cuts ultraviolet rays and infrared rays, dichroic mirrors 121, 123, 133 and 135, total reflection mirrors 125 and 131 that form color separation / combination means, and an optical path for each color-separated color. Liquid crystal panels 141, 143, 145 provided and a polarizing plate 1 serving as a polarizer provided on the light incident side of each liquid crystal panel.
51, 153, 155 and polarizing plates 161, 163, 165 serving as analyzers provided on the light emission side of each liquid crystal panel.
And a projection lens 171 for enlarging and projecting the color-combined light, a Fresnel lens 175 and a lenticular lens 177 serving as a screen, and a lenticular lens 1
A polarizing film 13 provided outside 77, a video input terminal 181, to which a video signal is input, a signal processing circuit 183 that generates a drive signal for driving the liquid crystal panels 141, 143 and 145 from the video signal, and a polarizing plate. 163 and the dichroic mirror 133, and the phase difference plate 15 as a polarization direction conversion means.

In the figure, the same components as those of the conventional rear projection type liquid crystal projector device 101 shown in FIG. 28 are designated by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 1, the rear projection type liquid crystal projector device 1 according to the first embodiment includes a polarizing plate 163 and a dichroic mirror 133 in addition to the conventional rear projection type liquid crystal projector device 101 shown in FIG. The lenticular lens 1 is provided with the phase difference plate 15 as the direction changing means.
The polarizing film 13 is provided outside 77, and when the polarization direction of the light transmitted through the polarizing plate 163 and reflected by the dichroic mirror 133 and the polarizing direction of the polarizing film 13 are different, the polarization of the light passing through the polarizing plate 163. The direction is converted by the retardation plate 15 to match the polarization direction of the polarizing film 13.

The retardation plate 15 is a λ / 2 wavelength plate which is provided between the polarizing plate 163 and the dichroic mirror 133 and has a phase difference of ½ wavelength between components orthogonal to each other.
The polarization direction of the light that has passed through the polarizing plate 163 (the polarization direction that forms an angle of approximately −45 degrees (or 135 degrees) with respect to the image scanning direction) is converted approximately 90 degrees clockwise, and the polarization direction of the polarization film 13 ( It is adjusted to the polarization direction which forms an angle of approximately 45 degrees with the image scanning direction.

As the phase difference plate 15, for example, a plastic sheet phase difference plate which applies a stress to a plastic sheet and produces a phase difference by the photoelastic effect of its residual strain,
Alternatively, a retardation plate made of a birefringent crystal that produces a retardation by using a birefringent crystal such as quartz or calcite having a desired thickness is used. Alternatively, a substance that causes or changes birefringence due to an electric field or a magnetic field may be used as the retardation plate 15, and the electric field or magnetic field applied to this substance may be changed to adjust the phase difference. In addition, this phase plate 15
Are arranged such that the converted polarization direction matches the polarization direction of the polarization film 13.

In the present embodiment, the liquid crystal panels 141, 143, and 145 are liquid crystal panels each having an oblique rubbing structure, and the liquid crystal panel 143 has another structure for the purpose of downsizing the projection unit. One liquid crystal panel 141
And 145 at right angles.

Therefore, the number of times the light passing through each liquid crystal panel is reflected by the dichroic mirror or the total reflection mirror for color combination is not the same between the liquid crystal panels. That is, the odd / even number of reflections of light that has passed through the other two liquid crystal panels is different from the even / even number of reflections of light that has passed through the liquid crystal panels that are arranged at a right angle to them. In the present embodiment, the number of reflections for color combination after transmission of the liquid crystal panels 141, 143, and 145 is 0, 1 respectively.
The number of times corresponding to the liquid crystal panels 141 and 145 is even, and the number of times corresponding to the liquid crystal panel 143 is odd.

FIG. 2 is a sectional view for explaining the details of the screen structure in the first embodiment. FIG. 2 (a)
Shows a configuration in which a Fresnel lens 175, a lenticular lens 177, a polarizing film 13 and an acrylic plate 11 as a light transmitting plate having an arbitrary transmittance are arranged in the order of image projection direction.

That is, in FIG. 2A, an arbitrary transmittance (for example, 80) is provided outside the lenticular lens 177.
%) Is provided, and the acrylic plate 1 is provided.
A polarizing film 13 made of iodine or the like, which has a high transmittance and a high degree of polarization among the polarizing plates, is attached to the inner surface of 1.
According to this configuration, the polarizing film 13 is protected by the outer acrylic plate 11, which is preferable from the viewpoint of the durability of the screen.

Further, according to the configuration of FIG. 2B, the Fresnel lens 175, the lenticular lens 177, the acrylic plate 11 as a light transmitting plate having an arbitrary transmittance, and the polarizing film 13 are arranged in the order of the image projection direction. are doing. According to this configuration, the efficiency of cutting the external light by the polarizing film 13 is the highest, but the configuration of FIG. 2A is more excellent in terms of protection of the polarizing film.

The polarizing film 13 can be arranged at any position from the projection lens 171 to the outside of the lenticular lens 177, but it does not pass through the liquid crystal panel or the dispersion characteristics of the Fresnel lens 175 and the lenticular lens 177. Depending on the state of stray light entering the screen, it may be provided on the incident surface side of the Fresnel lens 175 as shown in FIG. 2C or between the Fresnel lens 175 and the lenticular lens 177 as shown in FIG. 2D. Good.

Next, the operation of the first embodiment and the polarization direction of each part will be described with reference to FIGS. 3 and 4. In these drawings, the light source lamp 111, the power supply circuit 113, the UV / IR filter 117, the video input terminal 181, and the signal processing circuit 183 shown in FIG. 1 are omitted.

FIG. 3 shows a liquid crystal panel 14 for R (red).
3 is an operation explanatory diagram of the first embodiment in which a retardation plate 15 is arranged between an analyzer 164 of No. 3 and a dichroic mirror 133. FIG. Further, FIG. 4 is a diagram for explaining the polarization direction in each component, which is a matrix in which each optical element is arranged in the horizontal direction and the three primary colors of light are arranged in the vertical direction in the order of B, R, and G. ing. In addition, in the following description, unless otherwise specified, FIG. 4 (n) is a diagram showing the polarization direction in a single vertical line indicated by (n) in this matrix (n is from a to a). any character up to h).

In FIG. 3, B (blue) of the substantially parallel light obtained from the parabolic mirror 115 is reflected and separated by the dichroic mirror 121 arranged at an angle of 45 degrees with respect to the optical path, and then separated. R (red) by dichroic mirror 123 arranged at an angle of 45 degrees to the optical path
Is reflected and separated, and the remaining G (green) passes through the dichroic mirrors 121 and 123.

In this way, of the lights separated into the three primary colors of light, R, G, and B, B is reflected by the total reflection mirror 131 and enters the polarizing plate 151. After being reflected by the dichroic mirror 123, R is incident on the polarizing plate 153 and G is incident on the polarizing plate 155.

The light incident on each of the polarizing plates 151, 153, and 155 is natural light having no specific polarization direction, in other words, having a uniform polarization direction in all directions, as shown in FIG. 4A. . Then, each polarizing plate 15 which is a polarizer
When the light passes through 1, 153 and 155, it becomes light in a polarization direction having an angle of minus 45 degrees with the image scanning direction of the liquid crystal panel as shown in FIG.

Next, the respective polarizing plates 151, 153, 155
The liquid crystal panels 141 and 1 to which the light passing through corresponds, respectively.
When the light enters 43 and 145, these liquid crystal panels have a diagonal rubbing configuration, and therefore, when the voltage is on as shown in FIG.
The polarized light of the direction of minus 45 degrees and the image scanning direction indicated by the dashed arrow is transmitted as it is, but when the voltage is off, the polarization direction of the transmitted light is equal to the image scanning direction 4 as indicated by the solid arrow.
It turns in the direction of 5 degrees.

Next, as shown in FIG. 4 (d), only the polarization components in the direction of 45 degrees with respect to the image scanning direction are selectively transmitted by the polarizer plates 161, 163 and 165 which are analyzers. Next, as shown in FIG. 4E, the polarization direction of the light passing through the R analyzer (polarizing plate) 163 is the retardation plate 1.
5 turns counterclockwise by about 90 degrees, which is a direction of minus 45 degrees with respect to the image scanning direction.

Next, as shown in FIG. 4 (f), B and R are color-synthesized by the dichroic mirror 133. B simply passes through the dichroic mirror 133, while R passes through the dichroic mirror 133. Then, the light is reflected and the left and right are inverted, and the light is polarized in the direction of 45 degrees with respect to the image scanning direction.

This color-combined B and R are shown in FIG.
Through the dichroic mirror 135,
It enters the projection lens 171.

On the other hand, since G is reflected by the total reflection mirror 125 and the dichroic mirror 135,
The light transmitted through the analyzer (polarizing plate) 165 is switched left and right twice and enters the projection lens 171 in the original polarization direction.

The light that carries the color image and is incident on the projection lens 171 is projected as an image on the Fresnel lens 175. The projected image is condensed at the observation position by the Fresnel lens 175, and controlled and / or diffused by the lenticular lens 177 in an arbitrary direction. That is, the Fresnel lens 175 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 177 widens the viewing angle.

Then, as shown in FIG. 4H, the polarizing film 13 allows only the light polarized in the same direction as the image scanning direction to pass. At this time, since the polarization direction is converted to the same direction as the polarization direction of the polarizing film by the phase difference plate 17,
The image brightness and contrast do not decrease. Further, since the polarizing film 13 allows only light in the same direction as the polarization direction to pass therethrough, light other than light that has passed through the liquid crystal panels 141, 143, 145, such as stray light inside the rear projection type liquid crystal projector device or ambient light, can be obtained. Of these, the reflection of polarized light in the direction perpendicular to the image scanning direction can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

FIG. 5 is a system configuration diagram showing a second embodiment of a rear projection type liquid crystal projector device according to the present invention. In the figure, a rear projection type liquid crystal projector device 2 includes a light source lamp 111 serving as a light source and a light source lamp 1.
11, a power source circuit 113 for supplying power to the power source 11, an ellipsoidal mirror 114 arranged so that the light source lamp 111 is located at one focus, a UV / IR filter 117 for cutting ultraviolet rays and infrared rays, and an ellipsoidal mirror 114. And a dichroic mirror 121, 123, 1 which constitutes a color separation / combination means.
33 and 135, total reflection mirrors 125 and 131, and a liquid crystal panel 141 provided for each color-separated optical path of each color.
143 and 145, polarizing plates 151, 153 and 155 which are polarizers provided on the light incident side of each liquid crystal panel, and a polarizing plate 161 which is an analyzer provided on the light emitting side of each liquid crystal panel, 163 and 165, a projection lens 171 for enlarging and projecting the color-combined light incident thereon, a Fresnel lens, a lenticular lens 177 and a polarizing film 13 which form a screen, and an image input terminal 18 to which an image signal is input.
1 and the video signal from the liquid crystal panels 141, 143 and 14
5, a signal processing circuit 183 for generating a drive signal for 5,
Polarizing plate 163 and dichroic mirror 13 for the red light path
3, a phase difference plate 15 as a polarization direction conversion means, a dichroic mirror 135, and a projection lens 1.
71 and a retardation plate 17 as a polarization direction conversion unit provided between the optical disc 71 and the optical disc 71.

As shown in FIG. 5, the rear projection type liquid crystal projector device 2 of the second embodiment has a light source lamp 111 instead of the parabolic mirror 115 of the rear projection type liquid crystal projector device 1 shown in FIG. The substantially parallel light is obtained by the ellipsoidal mirror 114 and the condenser lens 116 arranged at one focus, and the dichroic mirror 135 and the projection lens 17 are used.
1 is different from that in FIG. 1 in that a retardation plate 17 as a polarization direction converting means is added, and the other constituent elements are the same. Therefore, the same reference numerals are given and detailed description thereof will be omitted.

The phase difference plate 15 is a λ / 2 wavelength plate similar to the phase difference plate used in the first embodiment, but the phase difference plate 17 has a phase difference of 1 between components orthogonal to each other. It is a λ / 4 wavelength plate that is a quarter wavelength, and converts the polarization direction of the color-combined light (the polarization direction forming an angle of about 45 degrees with respect to the image scanning direction) to about 45 degrees clockwise or counterclockwise. The polarization direction of the polarizing film 13 (the same direction as the image scanning direction or the direction perpendicular to the image scanning direction).

Further, the polarization direction of the polarizing film 13 is different from that of the first embodiment, and in the second embodiment, the polarization direction of the polarizing film 13 is the same as the image scanning direction (horizontal direction) or the image scanning direction. It is provided in a direction (vertical direction) at a right angle to.

First, the operation when the polarization direction of the polarizing film 13 is provided in the same direction as the image scanning direction (horizontal direction) will be described with reference to FIGS. 6 and 7. In these figures, the light source lamp 111 and the power supply circuit 1 shown in FIG.
13, UV / IR filter 117, condenser lens 116,
The video input terminal 181 and the signal processing circuit 183 are omitted.

In FIG. 6, the substantially parallel light obtained from the ellipsoidal mirror 114 and the condenser lens (not shown) is dichroic mirror 12 arranged at an angle of 45 degrees with respect to the optical path.
1, B is reflected and separated, and then the dichroic mirror 12 is arranged at an angle of 45 degrees with respect to the optical path.
R is reflected and separated by 3 and the remaining G passes through the dichroic mirrors 121 and 123.

In this way, of the lights separated into the three primary colors of light, R, G, and B, B is reflected by the total reflection mirror 131 and enters the polarizing plate 151. After being reflected by the dichroic mirror 123, R is incident on the polarizing plate 153 and G is incident on the polarizing plate 155.

The light incident on each of the polarizing plates 151, 153, and 155 is natural light that does not have a specific polarization direction, in other words, has a uniform polarization direction in all directions, as shown in FIG. 7A. . Then, each polarizing plate 15 which is a polarizer
When the light passes through 1, 153 and 155, it becomes light in a polarization direction having an angle of −45 degrees with the image scanning direction of the liquid crystal panel as shown in FIG. 7B.

Next, the respective polarizing plates 151, 153, 155
The liquid crystal panels 141 and 1 to which the light passing through corresponds, respectively.
When incident on 43 and 145, since these liquid crystal panels have a diagonal rubbing configuration, when the voltage is on as shown in FIG.
The polarized light of the direction of minus 45 degrees and the image scanning direction indicated by the dashed arrow is transmitted as it is, but when the voltage is off, the polarization direction of the transmitted light is equal to the image scanning direction 4 as indicated by the solid arrow.
It turns in the direction of 5 degrees.

Next, as shown in FIG. 7 (d), only the polarization components in the direction of 45 degrees with respect to the image scanning direction are selectively transmitted by the polarizer plates 161, 163, 165 which are analyzers. Next, as shown in FIG. 7E, the polarization direction of the light that has passed through the R analyzer (polarizing plate) 163 is the retardation plate 1.
By 5, the counterclockwise direction is swung by approximately 90 degrees, which is a direction of minus 45 degrees with respect to the image scanning direction.

Next, as shown in FIG. 7 (f), B and R are color-synthesized by the dichroic mirror 133. B simply passes through the dichroic mirror 133, while R passes through the dichroic mirror 133. Then, the light is reflected and the left and right are inverted, and the light is polarized in the direction of 45 degrees with respect to the image scanning direction.

The color-synthesized B and R are shown in FIG. 7 (g).
As shown in, the light passes through the dichroic mirror 135. On the other hand, since G is reflected by the total reflection mirror 125 and the dichroic mirror 135, the light transmitted through the analyzer (polarizing plate) 165 is switched right and left twice, and the original polarization direction (45 with respect to the image scanning direction) is changed. Degree direction)
Will be polarized.

The color-synthesized RGB is shown in FIG.
As shown in (h), the polarization direction is converted by the retardation plate 17 in the clockwise direction by about 45 degrees and is incident on the projection lens 171 in the polarization direction that matches the polarization direction of the polarization film 13 (the image scanning direction, the lateral direction). To do.

The light that carries the color image and enters the projection lens 171 is projected as an image on the Fresnel lens 175. The projected image is condensed at the observation position by the Fresnel lens 175, and controlled and / or diffused by the lenticular lens 177 in an arbitrary direction. That is, the Fresnel lens 175 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 177 widens the viewing angle.

Then, as shown in FIG. 7I, the polarizing film 13 allows only the light polarized in the same direction as the image scanning direction to pass therethrough. At this time, since the polarization direction is converted to the same direction as the polarization direction of the polarizing film by the phase difference plate 17,
The image brightness and contrast do not decrease. Further, since the polarizing film 13 allows only light in the same direction as the polarization direction to pass therethrough, light other than light that has passed through the liquid crystal panels 141, 143, 145, such as stray light inside the rear projection type liquid crystal projector device or ambient light, can be obtained. Minus 4 with respect to the image scanning direction
The reflection of polarized light in the direction of 5 degrees can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

Next, the operation when the polarization direction of the polarizing film 13 is provided in the direction (vertical direction) perpendicular to the image scanning direction will be described with reference to FIGS. 8 and 9. In these figures, the light source lamp 111, the power supply circuit 113, the UV / IR filter 117, and the condenser lens 11 shown in FIG.
6, the video input terminal 181 and the signal processing circuit 183 are omitted.

In FIG. 8, the substantially parallel light obtained from the ellipsoidal mirror 114 and the condenser lens (not shown) is dichroic mirror 12 arranged at an angle of 45 degrees with respect to the optical path.
1, B is reflected and separated, and then the dichroic mirror 12 is arranged at an angle of 45 degrees with respect to the optical path.
R is reflected and separated by 3 and the remaining G passes through the dichroic mirrors 121 and 123.

In the light thus separated into the three primary colors of light, R, G, and B, B is reflected by the total reflection mirror 131 and enters the polarizing plate 151. After being reflected by the dichroic mirror 123, R is incident on the polarizing plate 153 and G is incident on the polarizing plate 155.

The light incident on each of the polarizing plates 151, 153, and 155 is natural light that does not have a specific polarization direction, in other words, has a uniform polarization direction in all directions, as shown in FIG. 9A. . Then, each polarizing plate 15 which is a polarizer
When the light passes through 1, 153 and 155, it becomes light in a polarization direction having an angle of minus 45 degrees with the image scanning direction of the liquid crystal panel as shown in FIG. 9B.

Next, the respective polarizing plates 151, 153, 155
The liquid crystal panels 141 and 1 to which the light passing through corresponds, respectively.
When the light enters 43 and 145, these liquid crystal panels have a diagonal rubbing configuration. Therefore, according to the on / off state of the control voltage of each cell, when the voltage is on as shown in FIG.
The polarized light of the direction of minus 45 degrees and the image scanning direction indicated by the dashed arrow is transmitted as it is, but when the voltage is off, the polarization direction of the transmitted light is equal to the image scanning direction 4 as indicated by the solid arrow.
It turns in the direction of 5 degrees.

Next, as shown in FIG. 9D, the polarizers 161, 163, and 165, which are analyzers, selectively transmit only the polarization component in the direction of 45 degrees with respect to the image scanning direction. Then, as shown in FIG. 9E, the polarization direction of the light passing through the R analyzer (polarizing plate) 163 is the phase difference plate 1.
By 5, the counterclockwise direction is swung by approximately 90 degrees, which is a direction of minus 45 degrees with respect to the image scanning direction.

Next, as shown in FIG. 9 (f), B and R are color-combined by the dichroic mirror 133, but B simply passes through the dichroic mirror 133, while R passes through the dichroic mirror 133. Then, the light is reflected and the left and right are inverted, and the light is polarized in the direction of 45 degrees with respect to the image scanning direction.

The color-combined B and R are shown in FIG. 9 (g).
As shown in, the light passes through the dichroic mirror 135. On the other hand, since G is reflected by the total reflection mirror 125 and the dichroic mirror 135, the light transmitted through the analyzer (polarizing plate) 165 is switched right and left twice, and the original polarization direction (45 with respect to the image scanning direction) is changed. Degree direction)
Will be polarized.

The RGB colors thus synthesized are shown in FIG.
As shown in (h), the phase difference plate 17 converts the polarization direction approximately 45 degrees counterclockwise, and the projection lens 171 has a polarization direction that matches the polarization direction of the polarization film 13 (direction perpendicular to the image scanning direction). Incident on.

The light that carries the color image and enters the projection lens 171 is projected as an image on the Fresnel lens 175. The projected image is condensed at the observation position by the Fresnel lens 175, and controlled and / or diffused by the lenticular lens 177 in an arbitrary direction. That is, the Fresnel lens 175 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 177 widens the viewing angle.

Then, as shown in FIG. 9I, the polarizing film 13 allows only the light polarized in the direction perpendicular to the image scanning direction to pass therethrough. At this time, since the polarization direction is converted to the same direction as the polarization direction of the polarizing film by the phase difference plate 17, the brightness and contrast of the image are not lowered. Further, since the polarizing film 13 allows only light in the same direction as the polarization direction to pass therethrough, light other than light that has passed through the liquid crystal panels 141, 143, 145, such as stray light inside the rear projection type liquid crystal projector device or ambient light, can be obtained. Among these, the reflection of polarized light in the direction of minus 45 degrees with respect to the image scanning direction can be prevented. For this reason,
The rate of screen contrast reduction can be reduced.

The details of the screen structure in the second embodiment are the same as those in the first embodiment, as shown in FIG.
Since the configuration shown in (1) is applied as it is, detailed description will be omitted.

FIG. 10 is a system configuration diagram showing a third embodiment of a rear projection type liquid crystal projector device according to the present invention. In the figure, the rear projection type liquid crystal projector device 3 includes a light source lamp 111 as a light source, a power supply circuit 113 for supplying power to the light source lamp 111, and a parabola arranged so that the light source lamp 111 is located at a focal point. Face mirror 11
5, a UV / IR filter 117 that cuts ultraviolet rays and infrared rays, a polarizing plate 157 that is a common polarizer, and dichroic mirrors 121 and 12 that form color separation / synthesis means.
3, 133, 135, total reflection mirrors 125 and 131
And liquid crystal panels 141, 143, 145 provided for the respective color-separated light paths, and a polarizing plate 1 serving as a common analyzer.
67, a projection lens 171 for enlarging and projecting the color-combined lights, and a Fresnel lens 17 serving as a screen
5 and the lenticular lens 177, the polarizing film 13 provided outside the lenticular lens 177, a video input terminal 181 to which a video signal is input, and a drive signal for driving the liquid crystal panels 141, 143, and 145 from the video signal. Signal processing circuit 183, and phase difference plates 15 and 17 as polarization direction conversion means arranged in front of and behind liquid crystal panel 143.

In the figure, the same components as those of the rear projection type liquid crystal projector device 1 according to the first embodiment shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. .

As shown in FIG. 10, the rear projection type liquid crystal projector device 3 according to the third embodiment has polarizers 151, 15 of the rear projection type liquid crystal projector device 1 shown in FIG.
A common polarizer 157 is provided between the light source and the color separation / combination means in place of 3,1551, and the analyzers 161, 163,
Instead of 165, a common analyzer 167 is provided between the color separation / combination means and the projection lens, and phase difference plates 15 and 17 as polarization direction conversion means are provided before and after the liquid crystal panel 143.

The phase difference plates 15 and 17 are both λ / 2 wave plates in which the phase difference between the components orthogonal to each other is ½ wavelength, and the polarization direction of the light entering or exiting the liquid crystal panel 143 (image (Polarization direction that forms an angle of approximately 45 degrees with the scanning direction)
Is converted approximately 90 degrees counterclockwise to match the polarization direction of light entering or exiting another liquid crystal panel. The polarization direction of the polarization film 13 is a polarization direction forming an angle of approximately −45 degrees with respect to the image scanning direction.

FIG. 11 shows a liquid crystal panel 1 for R (red).
It is operation | movement explanatory drawing of 3rd Embodiment which arrange | positioned the phase difference plate 15 and 17 before and behind 43. FIG. Further, FIG. 12 is a diagram for explaining the polarization direction in each component. In FIG. 11, substantially parallel light obtained from the parabolic mirror 115 enters a polarizing plate 157 which is a polarizer common to the three liquid crystal panels. Light incident on the polarizing plate 157 is natural light having no specific polarization direction, in other words, having uniform polarization directions in all directions, as shown in FIG.

Then, after passing through the polarizing plate 157, FIG.
As shown in FIG. 2 (b), the light has a polarization direction having an angle of minus 45 degrees with the image scanning direction of the liquid crystal panel. The light passing through the polarizing plate 157 is separated by B (blue) reflected by the dichroic mirror 121 arranged at an angle of 45 degrees with respect to the optical path, and then arranged at an angle of 45 degrees with respect to the optical path. R (red) is reflected and separated by the dichroic mirror 123, and the remaining G (green) is transmitted through the dichroic mirrors 121 and 123. Here, R reflected by the dichroic mirror 123
, The polarization direction thereof is horizontally inverted as shown in FIG. 12 (c), and becomes approximately 45 degrees with respect to the image scanning direction.

In the light thus separated into the three primary colors of light, R, G, and B, B is reflected by the total reflection mirror 131 and enters the liquid crystal panel 141. R is reflected by the dichroic mirror 123, and then, as shown in FIG.
As shown in, the polarization direction of the light is rotated by about 90 degrees in the counterclockwise direction by the retardation plate 15, and enters the liquid crystal panel 143 in the direction of −45 degrees with respect to the image scanning direction.

Next, when the B, R, and G lights respectively enter the corresponding liquid crystal panels 141, 143, and 145, since these liquid crystal panels have a diagonal rubbing structure, the control voltage of each cell is turned on / off. , Fig. 12
As shown in (e), when the voltage is on, the polarized light in the image scanning direction indicated by the dashed arrow and the direction of minus 45 degrees is transmitted as it is, but when the voltage is off, the polarization direction of the transmitted light is the solid line. As shown by the arrow, the lens is turned in the direction of 45 ° with respect to the image scanning direction.

Next, as shown in FIG. 12 (f), the polarization direction of the R light passing through the liquid crystal panel 143 is turned counterclockwise by about 90 degrees by the phase difference plate 17, and is minus with respect to the image scanning direction. It becomes the direction of 45 degrees, and further, FIG.
As shown in (g), the light is reflected by the dichroic mirror 133 to become polarized light having a direction of 45 degrees with respect to the image scanning direction.

As shown in FIG. 12H, the B and R color-synthesized by the dichroic mirror 133 pass through the dichroic mirror 135 and enter the projection lens 171.

On the other hand, since G is reflected by the total reflection mirror 125 and the dichroic mirror 135,
The left and right sides are swapped twice to become the original polarization direction. In this way, the polarization direction of the light carrying the image, which is color-synthesized from B, R, and G, is 45 degrees with respect to the image scanning direction, and as shown in FIG. 12I, the polarization direction is with respect to the image scanning direction. Then, the light passes through an analyzer (polarizing plate) 167 set in the direction of 45 degrees and enters the projection lens 171.

The light carrying the color image which has entered the projection lens 171 is projected as an image on the Fresnel lens 175. The projected image is condensed at the observation position by the Fresnel lens 175, and controlled and / or diffused by the lenticular lens 177 in an arbitrary direction. That is, the Fresnel lens 175 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 177 widens the viewing angle.

Then, as shown in FIG. 12J, the polarizing film 13 allows only the light polarized in the same direction as the image scanning direction to pass. At this time, since the polarization direction is converted to the same direction as the polarization direction of the polarizing film by the phase difference plate 17, the brightness and contrast of the image are not lowered. Further, since the polarizing film 13 allows only light in the same direction as the polarization direction to pass therethrough, light other than light that has passed through the liquid crystal panels 141, 143, 145, such as stray light inside the rear projection type liquid crystal projector device or ambient light, can be obtained. Of these, the reflection of polarized light in the direction perpendicular to the image scanning direction can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

FIG. 13 is a system configuration diagram showing a fourth embodiment of a rear projection type liquid crystal projector device according to the present invention. As shown in FIG. 13, the rear projection type liquid crystal projector device 4 of the fourth embodiment includes an analyzer (polarizing plate) 167 and a projection lens 171 in addition to the rear projection type liquid crystal projector device 3 shown in FIG. The difference is that a retardation plate 19 as a polarization direction conversion means is added between
Since other components are the same, the same reference numerals are given and detailed description will be omitted.

The phase difference plates 15 and 17 are λ / 2 wavelength plates similar to the phase difference plates used in the third embodiment.
The phase difference plate 19 has a phase difference of 1/4 between components orthogonal to each other.
It is a λ / 4 wavelength plate which is a wavelength, and converts the polarization direction of the color-synthesized light (the polarization direction forming an angle of about 45 degrees with respect to the image scanning direction) clockwise or counterclockwise by about 45 degrees,
It is aligned with the polarization direction of the polarizing film 13 (the same direction as the image scanning direction or the direction perpendicular to the image scanning direction).

The polarization direction of the polarizing film 13 is different from that of the third embodiment. In the fourth embodiment, the polarization direction of the polarizing film 13 is the same as the image scanning direction (horizontal direction) or the image scanning direction. It is provided in a direction (vertical direction) at a right angle to.

First, the operation when the polarization direction of the polarization film 13 is provided in the same direction as the image scanning direction (horizontal direction) will be described with reference to FIGS. 14 and 15. FIG. 14 and FIG.
As shown in 5 (a) to 5 (i), the procedure from the incident light to the passage through the analyzer (polarizing plate) 167 is exactly the same as that of the third embodiment. As shown in FIG. 15J, when the color-combined light enters the phase difference plate 19, the polarization direction is converted by the phase difference plate 19 in the clockwise direction by about 45 degrees, and the polarization direction of the polarization film 13 (image scanning). (Direction, lateral direction) and enters the projection lens 171 in a polarization direction that matches the direction.

The light that carries the color image and enters the projection lens 171 is projected on the Fresnel lens 175 as an image. The projected image is condensed at the observation position by the Fresnel lens 175, and controlled and / or diffused by the lenticular lens 177 in an arbitrary direction. That is, the Fresnel lens 175 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 177 widens the viewing angle.

Then, as shown in FIG. 15K, the polarizing film 13 allows only the light polarized in the same direction as the image scanning direction to pass therethrough. At this time, since the polarization direction is converted to the same direction as the polarization direction of the polarizing film by the phase difference plate 19, the brightness and contrast of the image are not lowered. Further, since the polarizing film 13 allows only light in the same direction as the polarization direction to pass therethrough, light other than light that has passed through the liquid crystal panels 141, 143, 145, such as stray light inside the rear projection type liquid crystal projector device or ambient light, is emitted. Of these, the reflection of polarized light in the direction perpendicular to the image scanning direction can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

Next, the operation in the case where the polarization direction of the polarizing film 13 is provided perpendicularly to the image scanning direction (longitudinal direction) is shown in FIG.
6 and FIG. 17, a description will be given.

As shown in FIGS. 16 and 17A to 17I, the process from the incident light to the analyzer (polarizing plate) 167 is the same as that of the third embodiment. FIG.
As shown in (j), when the color-combined light enters the phase difference plate 19, the polarization direction of the phase difference plate 19 is converted approximately 45 degrees counterclockwise, and the polarization direction of the polarization film 13 (image scanning direction). To the projection lens 171.

The light that carries the color image and is incident on the projection lens 171 is projected as an image on the Fresnel lens 175. The projected image is condensed at the observation position by the Fresnel lens 175, and controlled and / or diffused by the lenticular lens 177 in an arbitrary direction. That is, the Fresnel lens 175 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 177 widens the viewing angle.

Then, as shown in FIG. 17K, the polarizing film 13 allows only the light polarized in the direction perpendicular to the image scanning direction to pass therethrough. At this time, since the polarization direction is converted to the same direction as the polarization direction of the polarizing film by the phase difference plate 19, the brightness and contrast of the image are not lowered. Further, since the polarizing film 13 allows only light in the same direction as the polarization direction to pass therethrough, light other than light that has passed through the liquid crystal panels 141, 143, 145, such as stray light inside the rear projection type liquid crystal projector device or ambient light, can be obtained. Of these, the reflection of polarized light in the same direction as the image scanning direction can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

FIG. 18 is a system configuration diagram showing a fifth embodiment of a rear projection type liquid crystal projector device according to the present invention. In the figure, the rear projection type liquid crystal projector device 5 includes a light source lamp 111 as a light source, a power supply circuit 113 for supplying power to the light source lamp 111, and a parabola arranged so that the light source lamp 111 is located at a focal point. Face mirror 11
5, a UV / IR filter 117 that cuts ultraviolet rays and infrared rays, a polarizing plate 157 that is a common polarizer, and dichroic mirrors 121 and 12 that form color separation / synthesis means.
3, 133, 135, total reflection mirrors 125 and 131
Liquid crystal panels 141, 143, and 145 provided for the respective color-separated light paths, a projection lens 171 for enlarging and projecting the color-combined light, and a Fresnel lens 175 and a lenticular lens 177 serving as a screen.
A polarizing film 13 provided outside the lenticular lens 177, and a video input terminal 181 to which a video signal is input.
And the liquid crystal panels 141, 143 and 145 from the video signal.
A signal processing circuit 183 for generating a drive signal for driving
The liquid crystal panel 143 is provided with front and rear phase difference plates 15 and 17 as polarization direction conversion means.

In the figure, the same components as those of the rear projection type liquid crystal projector device 3 according to the third embodiment shown in FIG. 10 are designated by the same reference numerals and detailed description thereof will be omitted. .

As shown in FIG. 18, in the rear projection type liquid crystal projector device 5 of the fifth embodiment, the polarizing plate 167 which is a common analyzer is removed from the rear projection type liquid crystal projector device 3 shown in FIG. However, the polarizing film 13 also has the function of an analyzer. The polarization direction of the polarization film 13 is a polarization direction forming an angle of approximately −45 degrees with respect to the image scanning direction. Other configurations and operations are similar to those of the third embodiment.

FIG. 19 is a diagram for explaining the operation of the fifth embodiment, and FIG. 20 is a diagram for explaining the polarization direction in each component.

As shown in FIGS. 19 and 20A to 20H, the process from the incident light to the transmission through the dichroic mirror 135 is exactly the same as that of the third embodiment.

Then, as shown in FIG. 20 (i), the polarizing film 13 allows only light polarized in the direction of 45 degrees with respect to the image scanning direction to pass therethrough, and also serves as an analyzer. In addition, the polarizing film 13 includes liquid crystal panels 141, 143, 145.
It is possible to prevent reflection of light other than the light that has passed through, for example, stray light inside the rear projection type liquid crystal projector device, and of ambient light, polarized light in a direction perpendicular to the polarization direction of the polarizing film 13. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

FIG. 21 is a system configuration diagram showing a sixth embodiment of a rear projection type liquid crystal projector device according to the present invention.

As shown in FIG. 21, in the rear projection type liquid crystal projector device 6 of the sixth embodiment, the analyzer (polarizing plate) 167 is removed from the rear projection type liquid crystal projector device 4 shown in FIG. Since the other components are the same, the same reference numerals are given and detailed description will be omitted.

Further, the difference between this embodiment and the fifth embodiment is that a phase difference plate 19 which is a λ / 4 wavelength plate is added, and the polarization direction of the color-combined light (in the image scanning direction is (The polarization direction that forms an angle of approximately 45 degrees) is converted into a clockwise direction or a counterclockwise direction by approximately 45 degrees, and is converted to the polarization direction of the polarizing film 13 (the same direction as the image scanning direction or the direction perpendicular to the image scanning direction). It is that they are aligned.

Further, the polarization direction of the polarization film 13 is different from that of the fifth embodiment, and in the sixth embodiment, the polarization direction of the polarization film 13 is the same as the image scanning direction (horizontal direction) or the image scanning direction. It is provided in a direction (vertical direction) at a right angle to.

First, the operation when the polarization direction of the polarization film 13 is provided in the same direction as the image scanning direction (horizontal direction) will be described with reference to FIGS. 22 and 23.

As shown in FIGS. 22 and 23A to 23H, the process from the incident light to the transmission through the dichroic mirror 135 is exactly the same as in the fifth embodiment. FIG.
As shown in (i), when the color-combined light enters the phase difference plate 19, the phase difference plate 19 converts the polarization direction of approximately 45 degrees clockwise, and the polarization direction of the polarization film 13 (image scanning direction, The light enters the projection lens 171 in a polarization direction that matches the (horizontal direction).

The light that carries the color image and enters the projection lens 171 is projected on the Fresnel lens 175 as an image. The projected image is condensed at the observation position by the Fresnel lens 175, and controlled and / or diffused by the lenticular lens 177 in an arbitrary direction. That is, the Fresnel lens 175 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 177 widens the viewing angle.

Then, in the polarizing film 13, as shown in FIG. 23J, only the light polarized in the same direction as the image scanning direction is transmitted. At this time, since the polarization direction is converted to the same direction as the polarization direction of the polarizing film by the phase difference plate 19, the brightness and contrast of the image are not lowered. Further, since the polarizing film 13 allows only light in the same direction as the polarization direction to pass therethrough, light other than light that has passed through the liquid crystal panels 141, 143, 145, such as stray light inside the rear projection type liquid crystal projector device or ambient light, can be obtained. Of these, the reflection of polarized light in the direction perpendicular to the image scanning direction can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

Next, the operation when the polarization direction of the polarization film 13 is provided perpendicularly to the image scanning direction (longitudinal direction) is shown in FIG.
4 and FIG. 25.

As shown in FIGS. 24 and 25A to 25H, the process from the incident light to the transmission through the dichroic mirror 135 is exactly the same as that of the fifth embodiment. FIG.
As shown in (i), when the color-combined light enters the phase difference plate 19, the polarization direction of the phase difference plate 19 is converted by about 45 degrees in the clockwise direction, and the polarization direction of the polarization film 13 (in the image scanning direction is changed). Projection lens 1 with a polarization direction that matches the vertical and vertical directions
It is incident on 71.

The light that carries the color image and enters the projection lens 171 is projected on the Fresnel lens 175 as an image. The projected image is condensed at the observation position by the Fresnel lens 175, and controlled and / or diffused by the lenticular lens 177 in an arbitrary direction. That is, the Fresnel lens 175 prevents the peripheral portion of the screen from becoming dark, and the lenticular lens 177 widens the viewing angle.

Then, as shown in FIG. 17 (j), the polarizing film 13 allows only the light polarized in the direction perpendicular to the image scanning direction to pass therethrough. At this time, since the polarization direction is converted to the same direction as the polarization direction of the polarizing film by the phase difference plate 19, the brightness and contrast of the image are not lowered. Further, since the polarizing film 13 allows only light in the same direction as the polarization direction to pass therethrough, light other than light that has passed through the liquid crystal panels 141, 143, 145, such as stray light inside the rear projection type liquid crystal projector device or ambient light, can be obtained. Of these, the reflection of polarized light in the same direction as the image scanning direction can be prevented. Therefore, it is possible to reduce the rate of reduction in the contrast of the screen.

In the fifth and sixth embodiments, the polarizing film 13 can be arranged at any position from the projection lens 171 to the outside of the lenticular lens 177. However, the Fresnel lens 175 and the lenticular lens 175 can be arranged. 177 or the liquid crystal panel 14 depending on the dispersion characteristics.
Depending on the state of the stray light component that does not pass through 1, 143, 145 and is diffused in the middle of the optical path and then reaches the screen, as shown in FIG. 2C, the incident surface side of the Fresnel lens 175, or FIG. It is preferable to provide it between the Fresnel lens 175 and the lenticular lens 177 as shown in FIG.

FIG. 26 is a system configuration diagram showing a seventh embodiment of a rear projection type liquid crystal projector device according to the present invention. The configuration of the rear projection type liquid crystal projector device 7 of the seventh embodiment is different from that of the first embodiment.
That is, the phase difference plate 17 is added between the dichroic mirror 135 and the projection lens 171, and the reflection mirror 179 is added between the projection lens 171 and the Fresnel lens 175. The optical path projected from the projection lens 171 to the screen is bent by the reflecting mirror 179, and the rear projection type liquid crystal projector device 7 is downsized.

In the present embodiment, the polarization direction is rotated by the phase difference plate 17 so that the light incident and reflected by the reflecting mirror 179 becomes S-polarized, so that the light projected from the projection lens 171 is reflected. The polarization direction of the mirror is 179
27 becomes S-polarized light, the reflectance Rs of the S-polarized component shown in FIG. 27 is applied, and the reflectance Rp of the P-polarized component is applied.
A higher reflectance is always obtained.

As a result, the attenuation of the light, which is enlarged and projected from the projection lens 171, toward the screen constituted by the Fresnel lens 175, the lenticular lens 177 and the polarizing film 13 by the reflecting mirror 179, is reduced, and the bright contrast is improved. The image is observed from the outside of the polarizing film 13.

The polarizing film 13 can be arranged at any position from the reflecting mirror 179 to the outside of the lenticular lens 177. For example, any of the arrangements shown in FIGS. 2A to 2D may be adopted.

The preferred embodiments have been described above, but these do not limit the present invention. For example, a liquid crystal panel having a general diagonal rubbing structure is used, but a product having a vertical rubbing structure or a horizontal rubbing structure can also be used. In this case, the polarization direction conversion means for converting the polarization direction of the light entering or exiting the liquid crystal panel arranged at a right angle to the other two liquid crystal panels is unnecessary, but the polarization of the color-combined light is eliminated. The polarization direction conversion means for matching the direction with the polarization direction of the polarizing film is effective.

[0129]

As described above, according to the present invention, 3
In the plate type rear projection type liquid crystal projector device, the polarization directions of the light emitted from the respective optical shutters are aligned by the polarization direction conversion means, and the same polarization direction as the light projected at any position from the projection lens to the front surface of the lenticular lens. By including the polarizing film having, it is possible to cut the polarization component perpendicular to the polarization direction of the polarizing film included in the external light reflected from the front surface (observation surface) of the lenticular lens.
There is an effect that the reflectance of external light can be reduced and the contrast of an image can be improved.

Further, according to the present invention, in the three-panel rear projection type liquid crystal projector device, the polarization direction converting means is arranged so that the polarization direction of the color-combined light coincides with the polarization direction of the polarizing film provided on the screen. By using the above conversion, a polarizing film having a desired polarization direction can be used regardless of the rubbing direction of the liquid crystal panel.

Further, according to the present invention, since the polarizing film acting as an analyzer is provided at any position from the projection lens of the rear projection type liquid crystal projector device to the front surface of the lenticular lens, the external light reflected from the front surface of the lenticular lens is provided. Since the polarization component perpendicular to the polarization direction of the polarizing film contained in the light can be cut, there is an effect that the reflectance of external light can be reduced and the contrast of the image can be improved.

Further, according to the present invention, by providing the light transmitting plate having an arbitrary transmittance, it is possible to further improve the contrast of the image.
Further, according to the present invention, a light transmitting plate having an arbitrary transmittance is further provided on the outside of the polarizing film to further improve the contrast of an image and prevent the polarizing film from being damaged by an external force. The effect is that you can.

Further, according to the present invention, in the rear projection type liquid crystal projector device of the type in which the reflection mirror is provided between the projection lens and the Fresnel lens, the polarization direction of the light emitted from the projection lens is changed to the reflection mirror. On the other hand, by using S-polarized light, the maximum reflectance of the reflecting mirror can be utilized, and there is an effect that the image can be brightened and the contrast can be improved.

[Brief description of drawings]

FIG. 1 is a system configuration diagram illustrating a first embodiment of a rear projection type liquid crystal projector device according to the present invention.

FIG. 2 is a sectional view illustrating a screen configuration of a rear projection type liquid crystal projector device according to the present invention.

FIG. 3 is an explanatory diagram of an optical path according to the first embodiment.

FIG. 4 is an explanatory diagram of a polarization direction according to the first embodiment.

FIG. 5 is a system configuration diagram illustrating a second embodiment of a rear projection type liquid crystal projector device according to the present invention.

FIG. 6 is an optical path explanatory diagram of the second embodiment.

FIG. 7 is an explanatory diagram of a polarization direction according to the second embodiment.

FIG. 8 is an explanatory diagram of an optical path according to the second embodiment.

FIG. 9 is an explanatory diagram of a polarization direction according to the second embodiment.

FIG. 10 is a system configuration diagram illustrating a third embodiment of a rear projection type liquid crystal projector device according to the present invention.

FIG. 11 is an optical path diagram of the third embodiment.

FIG. 12 is an explanatory diagram of a polarization direction according to the third embodiment.

FIG. 13 is a system configuration diagram illustrating a fourth embodiment of a rear projection type liquid crystal projector device according to the present invention.

FIG. 14 is an optical path explanatory diagram of the fourth embodiment.

FIG. 15 is an explanatory diagram of a polarization direction according to the fourth embodiment.

FIG. 16 is an optical path explanatory diagram of the fourth embodiment.

FIG. 17 is an explanatory diagram of a polarization direction according to the fourth embodiment.

FIG. 18 is a system configuration diagram illustrating a fifth embodiment of a rear projection type liquid crystal projector device according to the present invention.

FIG. 19 is an optical path explanatory diagram of the fifth embodiment.

FIG. 20 is an explanatory diagram of the polarization direction of the fifth embodiment.

FIG. 21 is a system configuration diagram illustrating a sixth embodiment of a rear projection type liquid crystal projector device according to the present invention.

FIG. 22 is an optical path explanatory diagram of the sixth embodiment.

FIG. 23 is an explanatory diagram of a polarization direction according to the sixth embodiment.

FIG. 24 is an explanatory diagram of an optical path according to the sixth embodiment.

FIG. 25 is an explanatory diagram of a polarization direction according to the sixth embodiment.

FIG. 26 is a system configuration diagram illustrating a seventh embodiment of a rear projection type liquid crystal projector device according to the present invention.

FIG. 27 is a graph showing the respective reflectances of S-polarized light and P-polarized light.

FIG. 28 is a system configuration diagram illustrating a configuration example of a conventional rear projection type liquid crystal projector device.

[Explanation of symbols]

1 ... Rear projection type liquid crystal projector device, 13 ... Polarizing film,
15, 17, 19 ... Retardation plate, 111 ... Light source lamp, 1
13 ... Power supply circuit, 115 ... Parabolic mirror 117 ... UV
IR filters, 121, 123, 133, 135 ... Dichroic mirrors, 125, 131 ... Total reflection mirrors, 1
41, 143, 145 ... Liquid crystal panels, 151, 153,
155 ... Polarizing plate (polarizer), 161, 163, 165 ...
Polarizing plate (analyzer), 171 ... Projection lens, 175 ... Fresnel lens, 177 ... Lenticular lens, 181 ... Image input terminal, 183 ... Signal processing circuit.

[Procedure amendment]

[Submission date] April 8, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

[Fig. 2]

FIG. 27

[Figure 3]

FIG. 4

[Figure 5]

FIG. 6

FIG. 7

[Figure 8]

[Figure 9]

FIG. 10

FIG. 11

FIG.

FIG. 13

FIG. 14

FIG.

FIG. 16

FIG.

FIG.

FIG.

FIG.

FIG. 21

FIG.

FIG. 23

FIG. 24

FIG. 25

FIG. 26

FIG. 28

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshimitsu Umezawa 1-9-2 Harara-cho, Fukaya-shi, Saitama Prefecture Fukaya Plant, Toshiba Corporation (72) Yutaka Saito 1-9-2 Hara-cho, Fukaya-shi, Saitama Shares Company Toshiba Fukaya Factory (72) Inventor Toshio Obayashi 1-9-2 Hararacho, Fukaya City, Saitama Prefecture Toshiba Fukaya Factory

Claims (9)

[Claims] 1. A light source lamp, a parabolic mirror that controls and reflects light emitted from the light source lamp into substantially parallel light, and substantially parallel light obtained from the parabolic mirror using a dichroic mirror and a total reflection mirror. Color separating / combining means for separating and recombining the light into the three primary colors of different primary colors, and the recombining means, and a liquid crystal having a polarizer and an oblique rubbing structure provided for each of the paths of the three primary colors of light. An optical shutter including a set of a panel and an analyzer, a projection lens for magnifying and projecting the color-combined light by the color separation / combination means, and a Fresnel lens for condensing the light emitted from the projection lens at an arbitrary position, A lenticular lens that controls and / or diffuses the light that has passed through this Fresnel lens, and is arranged at an arbitrary position from the projection lens to the front surface of the lenticular lens. A polarizing film, and a polarization direction converter arranged between at least one of the optical shutter and the projection lens, for converting the polarization direction of light passing through the optical shutter so as to match the polarization direction of the polarizing film. A rear projection type liquid crystal projector device comprising: 2. A light source lamp, an ellipsoidal mirror for reflecting and condensing light emitted from the light source lamp, and a condenser lens for making light emitted from the ellipsoidal mirror substantially parallel to the optical axis. Color separation / combining means for separating the substantially parallel light obtained from the condenser lens into different paths for each of the three primary colors of light using a dichroic mirror and a total reflection mirror, and then recombining the separated light, and separating these into three primary colors. An optical shutter provided for each path of light, each of which includes a polarizer, a liquid crystal panel having an oblique rubbing configuration, and an analyzer; and a projection lens for magnifying and projecting the light color-combined by the color separation / combination means. A Fresnel lens for condensing the light emitted from the projection lens at an arbitrary position; a lenticular lens for controlling and / or diffusing the light passing through the Fresnel lens in an arbitrary direction; And a polarizing film disposed at any position from the front side to the front surface of the lenticular lens, and disposed between at least one of the optical shutter and the projection lens, and the polarization direction of light passing through the optical shutter is the polarized light. A rear projection type liquid crystal projector device comprising: a polarization direction conversion means for converting the film so as to match the polarization direction of the film. 3. A light source lamp, a parabolic mirror which controls and reflects light emitted from the light source lamp into substantially parallel light, and a first parametric mirror which restricts and passes a polarization direction of substantially parallel light obtained from the parabolic mirror. And a color separation / combination means for separating the light that has passed through the first polarization plate into different paths for each of the three primary colors of light using a dichroic mirror and a total reflection mirror, and then recombining the separated light. A liquid crystal panel having a diagonal rubbing structure provided for each path of light separated into primary colors, and a second polarization for selectively passing only light in an arbitrary polarization direction out of the lights color-synthesized by the color separation / combination means. A plate, a projection lens that magnifies and projects the light that has passed through the second polarizing plate, a Fresnel lens that condenses the light emitted from the projection lens at an arbitrary position, and the light that has passed through the Fresnel lens in an arbitrary direction. To control A lenticular lens that diffuses or diffuses, a polarizing film that has the same polarization direction as the second polarizing plate, and is arranged at an arbitrary position from the projection lens to the front surface of the lenticular lens, and at least one liquid crystal panel Polarization direction conversion means for converting at least one polarization direction arranged between the projection lens and the polarization direction conversion means, and the light passing through the three liquid crystal panels and reaching the second polarizing plate. A rear projection type liquid crystal projector device characterized in that the polarization direction matches the polarization direction of the second polarizing plate. 4. A light source lamp, an ellipsoidal mirror for reflecting and condensing light emitted from the light source lamp, and a condensing lens for making light emitted from the elliptical mirror substantially parallel to the optical axis. A first polarizing plate for limiting and passing the polarization direction of the substantially parallel light obtained from the condenser lens, and the light passing through the first polarizing plate by using a dichroic mirror and a total reflection mirror, each of the three primary colors of light Color separation / combination means for separating and recombining into different paths for each, a liquid crystal panel having a diagonal rubbing structure provided for each path of the light separated into the three primary colors, and color combination by the color separation / combination means. Second polarizing plate that selectively passes only the light in the arbitrary polarization direction from the reflected light, a projection lens that magnifies and projects the light that has passed through the second polarizing plate, and the light emitted from this projection lens is arbitrary. Frenet to focus on the position A lens, a lenticular lens that controls and / or diffuses light that has passed through the Fresnel lens in an arbitrary direction, and has the same polarization direction transmission characteristics as the second polarizing plate, and an arbitrary distance from the projection lens to the front surface of the lenticular lens. A polarizing film arranged at the position of at least one, and at least one polarization direction conversion means for converting the polarization direction arranged between the at least one liquid crystal panel and the projection lens. 2. The rear projection type liquid crystal projector device, wherein the polarization direction of light passing through the liquid crystal panel and reaching the second polarizing plate is the same as the polarization direction of the second polarizing plate. 5. A light source lamp, a parabolic mirror that controls and reflects light emitted from the light source lamp into substantially parallel light, and a polarizing plate that limits the polarization direction of the substantially parallel light obtained from the parabolic mirror. And a color separation / combination means for separating the light passing through the polarizing plate into different paths for each of the three primary colors of light using a dichroic mirror and a total reflection mirror, and then recombining the separated light, and the light separated into the three primary colors. A liquid crystal panel having an oblique rubbing structure provided for each path, a projection lens for enlarging and projecting the color-combined light by the color separation / combination means, and condensing the light emitted from the projection lens at an arbitrary position. Fresnel lens, lenticular lens for controlling and / or diffusing light passing through the Fresnel lens in any direction, and any position from the projection lens to the front surface of the lenticular lens A polarizing film arranged to selectively transmit only light of an arbitrary polarization direction; and a polarization direction conversion means arranged to convert at least one polarization direction between the at least one liquid crystal panel and the projection lens. The rear projection type liquid crystal projector device, wherein the polarization direction of the light passing through the liquid crystal panel and reaching the polarizing film coincides with the polarization direction of the polarizing film. 6. A light source lamp, an ellipsoidal mirror for reflecting and condensing light emitted from the light source lamp, and a condenser lens for making light emitted from the ellipsoidal mirror substantially parallel to the optical axis. A polarizing plate that restricts the polarization direction of the substantially parallel light obtained from the condenser lens, and the light that has passed through this polarizing plate is separated into different paths for each of the three primary colors of light using a dichroic mirror and a total reflection mirror. Then, a color separation / combination means for recombining, a liquid crystal panel having an oblique rubbing configuration provided for each of the light paths separated into the three primary colors, and the light color-combined by the color separation / combination means are enlarged and projected. A projection lens, a Fresnel lens that condenses the light emitted from this projection lens at an arbitrary position, and a lenticular lens that controls and / or diffuses the light that has passed through this Fresnel lens in an arbitrary direction, A polarizing film disposed at an arbitrary position from the projection lens to the front surface of the lenticular lens and selectively transmitting only light of an arbitrary polarization direction, and disposed between at least one of the liquid crystal panel and the projection lens. And a polarization direction conversion means for converting at least one polarization direction, wherein the polarization direction of the light passing through the liquid crystal panel and reaching the polarization film matches the polarization direction of the polarization film. A characteristic rear projection type liquid crystal projector device. 7. The polarizing film is arranged outside the lenticular lens, and a light transmitting plate having an arbitrary transmittance is further provided outside the polarizing film. 9. The rear projection type liquid crystal projector device according to any one of 1 above. 8. The polarizing film is arranged outside the lenticular lens, and a light transmitting plate having an arbitrary transmittance is further provided between the lenticular lens and the polarizing film. To claim 1
Rear projection type liquid crystal projector device according to the item. 9. A reflection mirror is further provided between the projection lens and the Fresnel lens, and a polarization direction of light emitted from the projection lens is S-polarized with respect to the reflection mirror. A rear projection type liquid crystal projector device according to any one of claims 1 to 8.